The term “header” as used commonly and as used in this specification is intended to include both headers carried on self propelled machines, which may therefore not include wheels mounted on the header itself, and headers which are towed behind a tractor and thus may include wheels attached to the header frame or to a component supporting the header.
Forage harvesting machines that condition forage and then deposit the forage into a windrow for drydown and subsequent harvesting are commonly used. Various types of forming baffles, fins, and shields are used to process the forage as it is ejected from the conditioner so that the windrow width, shape, uniformity and density are controlled.
A variety of preferences on width and height are common are used depending on operator preferences. These depend on climate factors such as wind, sun, precipitation, morning dew and other preferences such minimizing solar bleaching and also depend on the subsequent methods used to harvest the forage.
Fast drying in general is very important since getting the forage harvested quickly from the field by baling the windrow reduces the amount of degradation of quality from sun and morning dews and the risk of rapid degradation that occurs from precipitation and accelerated decomposition.
In practice wide conditioners are desirable and have become widely accepted as these give superior capacity and improved conditioning to the crop. Thus, most of the machines on the market feature conditioners that are wider than the resultant windrows commonly formed. A common problem therefore, is that of controlling and guiding the web of crop material issuing from the conditioner and controlling this to reduce in width to form the narrower the windrow which is required.
Many designs thus include side guide panels which engage side portions of the web of crop material with the intention of moving that portion of the crop at the side edges inwardly. In many cases, conventional designs have the disadvantage of the formation of concentrated crop streams as the edges of the flow are deflected inward to form a windrow narrower than the conditioner. Such concentrated crop streams interfere with the requirement for uniformity or constant density and thus will increase drying time.
A number of arrangements also use center deflector panels which engage the web or stream of crop material from above and thus direct the crop material downwardly in a more concentrated stream.
One example of a crop deflector plate is shown in U.S. Pat. No. 4,858,419 issued Aug. 22nd 1989 to Paul Bernier which discloses a top panel resting on fluffy crops such as flax to compress this into the stubble. This is not however used in conjunction with a crop conditioner.
Where such deflector plates are used, they generally have a fixed width equal to the full width of the web issuing from the conditioner and the job of concentrating the web to reduce its width is effected wholly by the side plates.